Rare-earth oxide based chamber material

ABSTRACT

An article comprises a plasma resistant ceramic material comprising 40-60 mol % of Y 2 O 3 , 35-50 mol % of ZrO 2 , and 10-20 mol % of Al 2 O 3 .

RELATED APPLICATIONS

This patent application is a continuation application of U.S.application Ser. No. 15/211,933, filed Jul. 15, 2016, which is adivisional application of U.S. application Ser. No. 14/531,785, filedNov. 3, 2014, which claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Application No. 61/903,215, filed Nov. 12, 2013, all ofwhich are incorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present invention relate, in general, to plasmaresistant rare-earth oxide materials, and in particular to solidsintered ceramic articles formed from the plasma resistant rare-earthoxide materials.

BACKGROUND

In the semiconductor industry, devices are fabricated by a number ofmanufacturing processes producing structures of an ever-decreasing size.Some manufacturing processes such as plasma etch and plasma cleanprocesses expose a substrate to a high-speed stream of plasma to etch orclean the substrate. The plasma may be highly corrosive, and may corrodeprocessing chambers and other surfaces that are exposed to the plasma.This corrosion may generate particles, which frequently contaminate thesubstrate that is being processed, contributing to device defects.Additionally, the corrosion may cause metal atoms from chambercomponents to contaminate processed substrates (e.g., processed wafers).

As device geometries shrink, susceptibility to defects and metalcontamination increases, and particle contaminant specifications andmetal contaminant specifications become more stringent. Accordingly, asdevice geometries shrink, allowable levels of particle defects and metalcontamination may be reduced. To minimize particle defects and metalcontamination introduced by plasma etch and/or plasma clean processes,chamber materials have been developed that are resistant to plasmas.Examples of such plasma resistant materials include ceramics composed toAl₂O₃, AlN, SiC and Y₂O₃. However, the plasma resistance properties ofthese ceramic materials may be insufficient for some applications. Forexample, plasma resistant ceramic lids and/or nozzles that aremanufactured using traditional ceramic manufacturing processes mayproduce unacceptable levels of particle defects when used in plasma etchprocesses of semiconductor devices with critical dimensions of 90 nm orlower.

SUMMARY

In one example implementation, an article comprises a plasma resistantceramic material comprising 40-60 mol % of Y₂O₃, 35-50 mol % of ZrO₂,and 10-20 mol % of Al₂O₃.

In another example implementation, an article comprise a metal portionand a solid sintered ceramic portion bonded to the metal portion. Thesolid sintered ceramic portion comprises a plasma resistant ceramicmaterial comprising 40-60 mol % of Y₂O₃, 35-50 mol % of ZrO₂, and 10-20mol % of Al₂O₃.

In another example implementation, an article comprises a body and aplasma resistant ceramic coating on at least one surface of the body.The plasma resistant ceramic coating comprises a plasma resistantceramic material comprising 40-60 mol % of Y₂O₃, 35-50 mol % of ZrO₂,and 10-20 mol % of Al₂O₃.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 is a sectional view of a semiconductor processing chamber havingone or more chamber components that are solid sintered ceramic articlescreated using ceramic materials provided in embodiments herein.

FIG. 2 illustrates a process for forming a solid sintered ceramicarticle, in accordance with one embodiment of the present invention.

FIG. 3 shows sputter resistance of various solid sintered ceramicarticles to a plasma generated under a bias power of 2200 Watts, inaccordance with embodiments of the present invention.

FIG. 4 shows erosion resistance of various solid sintered ceramicarticles to a plasma generated using an N₂/H₂ chemistry, in accordancewith embodiments of the present invention.

FIG. 5 shows erosion resistance of various solid sintered ceramicarticles to a plasma generated using a CHF₄/CF₄ chemistry, in accordancewith embodiments of the present invention.

FIG. 6A is a chart showing erosion resistance of various solid sinteredceramic articles to a plasma generated using an N₂/H₂ chemistry, inaccordance with embodiments of the present invention.

FIG. 6B is a chart showing pre-etch and post-etch roughness for variousbulk sintered ceramic articles.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the invention are directed to new sintered ceramicmaterials and to methods of manufacturing these new sintered ceramicmaterials. In embodiments, the sintered ceramic materials may have asolid solution that includes Y₂O₃ at a concentration of approximately 30molar % to approximately 60 molar %, Er₂O₃ at a concentration ofapproximately 20 molar % to approximately 60 molar %, and at least oneof ZrO₂, Gd₂O₃ or SiO₂ at a concentration of approximately 0 molar % toapproximately 30 molar %. In other embodiments, the sintered ceramicmaterials may have a solid solution that includes a mixture of Y₂O₃,ZrO₂, and/or Al₂O₃. The new sintered ceramic materials may be used tocreate chamber components for a plasma etch reactor. Use of chambercomponents created with the new sintered ceramic materials describedherein in a plasma etch reactor may cause on wafer metal contaminationand/or particle defects to be greatly reduced as compared to use ofchamber components created with conventional plasma resistant ceramicmaterials. In particular, metal contamination of yttrium, aluminum andzinc may be greatly reduced by use of the ceramic materials described inembodiments herein. Reduction of these metal contaminants on processedwafers may be dictated by manufacturers of semiconductors, displays,photovoltaics, micro-electro-mechanical systems (MEMS)) devices and soforth.

When the terms “about” and “approximate” are used herein, this isintended to mean that the nominal value presented is precise within±10%.

Embodiments are described with reference to solid sintered ceramicarticles that are chamber components for a plasma etch reactor (alsoreferred to as a plasma etcher). For example, the ceramic articles maybe process kit rings, chamber lid, gas distribution plates, showerheads, electrostatic chucks, and lift pins. However, the solid sinteredceramic materials described herein may also be used for other deviceshaving components that are exposed to a plasma environment, such as aplasma cleaner, a plasma propulsion system, and so forth. Moreover,embodiments are described with reference to solid sintered ceramicarticles. However, discussed embodiments also apply to deposited ceramiccoatings, such as plasma sprayed ceramic coatings and ceramic coatingsapplied using ion assisted deposition (IAD) techniques. Accordingly, itshould be understood that discussion of solid sintered ceramic materialsalso applies to deposited ceramic materials of the same compositions.

Embodiments are described herein with reference to ceramic articles thatcause reduced particle defects and metal contamination when used in aprocess chamber for plasma etch and/or plasma clean processes. However,it should be understood that the ceramic articles discussed herein mayalso provide reduced particle defects and metal contamination when usedin process chambers for other processes such as plasma enhanced chemicalvapor deposition (PECVD), plasma enhanced physical vapor deposition(PEPVD), plasma enhanced atomic layer deposition (PEALD), and so forth,and non-plasma etchers, non-plasma cleaners, chemical vapor deposition(CVD) furnaces, physical vapor deposition (PVD) furnaces, and so forth.

FIG. 1 is a sectional view of a semiconductor processing chamber 100having one or more chamber components that are solid sintered ceramicarticles created using ceramic materials provided in embodiments herein.The processing chamber 100 may be used for processes in which acorrosive plasma environment is provided. For example, the processingchamber 100 may be a chamber for a plasma etch reactor (also known as aplasma etcher), a plasma cleaner, and so forth. Examples of chambercomponents that may be composed of or include a solid sintered plasmaresistant ceramic material include an electrostatic chuck (ESC) 150, aring (e.g., a process kit ring or single ring), a chamber wall, a gasdistribution plate, a showerhead, a liner, a liner kit, a chamber lid104, a nozzle 132, and so on. The solid sintered ceramic material usedto form one or more of these chamber components is described in moredetail below with reference to FIG. 2.

In one embodiment, the processing chamber 100 includes a chamber body102 and a lid 130 that enclose an interior volume 106. The lid 130 mayhave a hole in its center, and the nozzle 132 may be inserted into thehole. In some embodiments, a showerhead is used instead of the lid 130and nozzle 132. The chamber body 102 may be fabricated from aluminum,stainless steel or other suitable material. The chamber body 102generally includes sidewalls 108 and a bottom 110. Any of the lid 130,nozzle 132, showerhead, and so on may include the solid sintered ceramicmaterial.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102. Outer liner 116 can be a plasma resistant layermade from rare earth oxide based materials.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The lid 130 may be supported on the sidewall 108 of the chamber body102. The lid 130 may be opened to allow access to the interior volume106 of the processing chamber 100, and may provide a seal for theprocessing chamber 100 while closed. A gas panel 158 may be coupled tothe processing chamber 100 to provide process and/or cleaning gases tothe interior volume 106 through the nozzle 132.

Examples of processing gases that may be used to process substrates inthe processing chamber 100 include halogen-containing gases, such asC₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃and SiF₄, among others, and other gases such as O₂, or N₂O. Examples ofcarrier gases include N₂, He, Ar, and other gases inert to process gases(e.g., non-reactive gases). A substrate support assembly 148 is disposedin the interior volume 106 of the processing chamber 100 below the lid130. The substrate support assembly 148 holds the substrate 144 duringprocessing. A ring 147 (e.g., a single ring) may cover a portion of theelectrostatic chuck 150, and may protect the covered portion fromexposure to plasma during processing. The ring 147 may be formed of anyof the solid sintered ceramic materials described herein.

An inner liner 118 may be formed on the periphery of the substratesupport assembly 148. The inner liner 118 may be a halogen-containinggas resistant material such as those discussed with reference to theouter liner 116.

In one embodiment, the substrate support assembly 148 includes amounting plate 162 supporting a pedestal 152, and an electrostatic chuck150. The electrostatic chuck 150 further includes a thermally conductivebase 164 and an electrostatic puck 166 bonded to the thermallyconductive base by a bond 138, which may be a silicone bond in oneembodiment. The mounting plate 162 is coupled to the bottom 110 of thechamber body 102 and includes passages for routing utilities (e.g.,fluids, power lines, sensor leads, etc.) to the thermally conductivebase 164 and the electrostatic puck 166.

The thermally conductive base 164 and/or electrostatic puck 166 mayinclude one or more optional embedded heating elements 176, embeddedthermal isolator 174 and/or conduits 168, 170 to control a lateraltemperature profile of the substrate support assembly 148. The conduits168, 170 may be fluidly coupled to a fluid source 172 that circulates atemperature regulating fluid through the conduits 168, 170. The embeddedthermal isolator 174 may be disposed between the conduits 168, 170 inone embodiment. The heating elements 176 are regulated by a heater powersource 178. The conduits 168, 170 and heating elements 176 may beutilized to control the temperature of the thermally conductive base164, thereby heating and/or cooling the electrostatic puck 166 and asubstrate (e.g., a wafer) 144 being processed. The temperature of theelectrostatic puck 166 and the thermally conductive base 164 may bemonitored using a plurality of temperature sensors 190, 192, which maybe monitored using a controller 195.

The electrostatic puck 166 may further include multiple gas passagessuch as grooves, mesas and other surface features that may be formed inan upper surface of the electrostatic puck 166. The gas passages may befluidly coupled to a source of a heat transfer (or backside) gas such asHe via holes drilled in the electrostatic puck 166. In operation, thebackside gas may be provided at controlled pressure into the gaspassages to enhance the heat transfer between the electrostatic puck 166and the substrate 144.

The electrostatic puck 166 includes at least one clamping electrode 180controlled by a chucking power source 182. The at least one clampingelectrode 180 (or other electrode disposed in the electrostatic puck 166or conductive base 164) may further be coupled to one or more RF powersources 184, 186 through a matching circuit 188 for maintaining a plasmaformed from process and/or other gases within the processing chamber100. The RF power sources 184, 186 are generally capable of producing RFsignal having a frequency from about 50 kHz to about 3 GHz and a powerof up to about 10,000 Watts.

FIG. 2 is a flow chart showing a process 200 for manufacturing a solidsintered ceramic article, in accordance with one embodiment of thepresent invention. At block 255, ceramic powders that are to be used toform the ceramic article are selected. Quantities of the selectedceramic powders are also selected.

In one embodiment, the selected ceramic powders include Y₂O₃, Er₂O₃, andone or more additional rare earth oxides that will form a phase with theY₂O₃ and the Er₂O₃. The additional rare earth oxides should also beerosion resistant and have a high density (low porosity). Examples ofthe additional rare earth oxides that may be used include ZrO₂ andGd₂O₃. Non-rare earth oxides can also be used such as Al₂O₃ & SiO₂. Inone embodiment, the ceramic powders include Y₂O₃ at a concentration ofapproximately 30 molar % (mol %) to approximately 60 molar %, Er₂O₃ at aconcentration of approximately 20 molar % to approximately 60 molar %,and at least one of ZrO₂, Gd₂O₃ or SiO₂ at a concentration ofapproximately 0 molar % to approximately 30 molar %. In one embodiment,the selected ceramic powders include Y₂O₃ at a concentration ofapproximately 30-60 molar %, Er₂O₃ at a concentration of approximately20-55 molar %, and one or more of ZrO₂ at a concentration of up to 20molar %, Gd₂O₃ at a concentration of up to 20 molar %, and SiO₂ at aconcentration of up to 30 molar %.

One specific mixture of ceramic powders that may be used (termed example1++) includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂at a concentration of approximately 5 molar %, Er₂O₃ at a concentrationof approximately 35 molar %, Gd₂O₃ at a concentration of approximately 5molar %, and SiO₂ at a concentration of approximately 15 molar %.Another specific mixture of ceramic powders that may be used (termedexample 2++) includes Y₂O₃ at a concentration of approximately 45 molar%, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ at aconcentration of approximately 35 molar %, Gd₂O₃ at a concentration ofapproximately 10 molar %, and SiO₂ at a concentration of approximately 5molar %. Another specific mixture of ceramic powders that may be used(termed example 3++) includes Y₂O₃ at a concentration of approximately40 molar %, ZrO₂ at a concentration of approximately 5 molar %, Er₂O₃ ata concentration of approximately 40 molar %, Gd₂O₃ at a concentration ofapproximately 7 molar %, and SiO₂ at a concentration of approximately 8molar %. Another specific mixture of ceramic powders that may be used(termed example 4++) includes Y₂O₃ at a concentration of approximately37 molar %, ZrO₂ at a concentration of approximately 8 molar %, andEr₂O₃ at a concentration of approximately 55 molar %. Another specificmixture of ceramic powders that may be used (termed example 5++)includes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at aconcentration of approximately 10 molar %, Er₂O₃ at a concentration ofapproximately 30 molar %, and Gd₂O₃ at a concentration of approximately20 molar %.

In one embodiment, the selected ceramic powders include 40-60 mol % ofY₂O₃, 30-50 mol % of ZrO₂, and 10-20 mol % of Al₂O₃. In anotherembodiment, the selected ceramic powders include 40-50 mol % of Y₂O₃,20-40 mol % of ZrO₂, and 20-40 mol % of Al₂O₃. In another embodiment,the selected ceramic powders include 70-90 mol % of Y₂O₃, 0-20 mol % ofZrO₂, and 10-20 mol % of Al₂O₃. In another embodiment, the selectedceramic powders include 60-80 mol % of Y₂O₃, 0-10 mol % of ZrO₂, and20-40 mol % of Al₂O₃. In another embodiment, the selected ceramicpowders include 40-60 mol % of Y₂O₃, 0-20 mol % of ZrO₂, and 30-40 mol %of Al₂O₃. In another embodiment, the selected ceramic powders include40-100 mol % of Y₂O₃, 0-60 mol % of ZrO₂, and 0-5 mol % of Al₂O₃.

In one embodiment, the selected ceramic powders include 40-100 mol % ofY₂O₃, 0-60 mol % of ZrO₂, and 0-5 mol % of Al₂O₃. In a first example(termed example 1+), the selected ceramic powders include 73-74 mol % ofY₂O₃ and 26-27 mol % of ZrO₂. In a second example (termed example 2+),the selected ceramic powders include 71-72 mol % of Y₂O₃, 26-27 mol % ofZrO₂, and 1-2 mol % of Al₂O₃. In a third example (termed example 3+),the selected ceramic powders include 64-65 mol % of Y₂O₃ and 35-36 mol %of ZrO₂. In a fourth example (termed example 4+), the selected ceramicpowders include 63-64 mol % of Y₂O₃, 35-36 mol % of ZrO₂, and 1-2 mol %of Al₂O₃. In a fifth example (termed example 5+), the selected ceramicpowders include 57-58 mol % of Y₂O₃, 42-43 mol % of ZrO₂. In a sixthexample (termed example 6+), the selected ceramic powders include 52-53mol % of Y₂O₃, 47-48 mol % of ZrO₂.

Any of the aforementioned sintered solids may include trace amounts ofother materials such as ZrO₂, Al₂O₃, SiO₂, B₂O₃, Er₂O₃, Nd₂O₃, Nb₂O₅,CeO₂, Sm₂O₃, Yb₂O₃, or other oxides.

At block 260, the selected ceramic powders are mixed. In one embodiment,the selected powders are mixed with water, a binder and a deflocculantto form a slurry. In one embodiment, the ceramic powders are combinedinto a granular powder by spray drying.

At block 265, a green body (an unsintered ceramic article) is formedfrom the mixed powders (e.g., from the slurry formed from a mixture ofthe selected ceramic powders). The green body can be formed usingtechniques including, but not limited to, slip casting, tape casting,cold isostatic pressing, unidirectional mechanical pressing, injectionmolding, and extrusion. For example, the slurry may be spray dried,placed into a mold, and pressed to form the green body in oneembodiment.

At block 270, the green body is sintered. Sintering the green body mayinclude heating the green body to a high temperature that is below themelting point of any of the constituent rare earth oxides in the greenbody. For example, if the green body includes Y₂O₃, Er₂O₃, ZrO₂, Gd₂O₃or SiO₂, then the green body may be heated to any point below themelting points of Y₂O₃, Er₂O₃, ZrO₂, Gd₂O₃ and SiO₂. In one embodiment,the sintering is preceded by heating the green body to a low temperatureto burn off a binder that was used in the formation of the green body.The green bodies can be sintered at 1500-2100° C. for a time of 3-30hours (hr).

The sintering process produces a solid sintered ceramic article thatincludes at least one solid solution made up of the various constituentceramic materials in a single phase. For example, in one embodiment, thesolid sintered ceramic article includes a solid solution that includesY₂O₃ at a concentration of approximately 30 molar % to approximately 60molar %, Er₂O₃ at a concentration of approximately 20 molar % toapproximately 50 molar %, and at least one of ZrO₂, Gd₂O₃ or SiO₂ at aconcentration of approximately 0 molar % to approximately 30 molar %.

In various embodiments, the solid sintered ceramic article may be usedfor different chamber components of a plasma etch reactor. Depending onthe particular chamber component that is being produced, the green bodymay have different shapes. For example, if the ultimate chambercomponent is to be a process kit ring, then the green body may be in theshape of a ring. If the chamber component is to be an electrostatic puckfor an electrostatic chuck, then the green body may be in the shape of adisc. The green body may also have other shapes depending on the chambercomponent that is to be produced.

The sintering process typically changes the size of the ceramic articleby an uncontrolled amount. Due at least in part to this change in size,the ceramic article is typically machined after the sintering process iscompleted at block 275. The machining may include surface grindingand/or polishing the ceramic article, drilling holes in the ceramicarticle, cutting and/or shaping the ceramic article, grinding theceramic article, polishing the ceramic article (e.g., using chemicalmechanical planarization (CMP), flame polishing, or other polishingtechniques), roughening the ceramic article (e.g., by bead blasting),forming mesas on the ceramic article, and so forth.

The ceramic article may be machined into a configuration that isappropriate for a particular application. Prior to machining, theceramic article may have a rough shape and size appropriate for aparticular purpose (e.g., to be used as a lid in a plasma etcher).However, the machining may be performed to precisely control size,shape, dimensions, hole sizes, and so forth of the ceramic article.

Depending on the particular chamber component that is to be produced,additional processing operations may additionally be performed. In oneembodiment, the additional processing operations include bonding thesolid sintered ceramic article to a metal body (block 280). In someinstances, in which the solid sintered ceramic article is both machinedand bonded to a metal body, the machining may be performed first,followed by the bonding. In other instances, the solid sintered ceramicarticle may first be bonded to a metal body, and may then be machined.In other embodiments, some machining is performed both before and afterthe bonding. Additionally, in some embodiments the solid sinteredceramic article may be bonded to another ceramic article.

In a first example, the ceramic article is to be used for a showerhead.In such an embodiment, many holes may be drilled into the ceramicarticle, and the ceramic article may be bonded to an aluminum gasdistribution plate. In a second example, the ceramic article is used foran electrostatic chuck. In such an embodiment, helium pin holes aredrilled into the ceramic article (e.g., by laser drilling), and theceramic article may be bonded by a silicone bond to an aluminum baseplate. In another example, the ceramic article is a ceramic lid. Sincethe ceramic lid has a large surface area, the ceramic lid formed fromthe new sintered ceramic material may have a high structural strength toprevent cracking or buckling during processing (e.g., when a vacuum isapplied to a process chamber of the plasma etch reactor). In otherexamples, a nozzle, a process kit ring, or other chamber component isformed.

FIG. 3 is a chart showing sputter resistance of various solid sinteredceramic articles to a plasma generated under a bias power of 2200 Watts,in accordance with embodiments of the present invention. The chart showsa sputter erosion rate of between 0.10 and 0.15 nanometer perradiofrequency hour (nm/RFhr) for a first example solid sintered ceramicarticle (example 1+) composed of 73.13 molar % Y₂O₃ and 26.87 molar %ZrO₂. The chart shows a sputter erosion rate of between 0.15 and 0.20nm/RFhr for a fourth example solid sintered ceramic article (example 4+)composed of 63.56 molar % Y₂O₃, 35.03 molar % ZrO₂, and 1.41 molar %Al₂O₃. The chart shows a sputter erosion rate of between 0.15 and 0.20nm/RFhr for a second example solid sintered ceramic article (example 2+)composed of 71.96 molar % Y₂O₃, 26.44 molar % ZrO₂, and 1.60 molar %Al₂O₃. The chart shows a sputter erosion rate of between 0.20 and 0.25nm/RFhr for a third example solid sintered ceramic article (example 3+)composed of 64.46 molar % Y₂O₃ and 35.54 molar % ZrO₂. The chart shows asputter erosion rate of between 0.25 and 0.30 nm/RFhr for a sixthexample solid sintered ceramic article (example 6+) composed of 52.12molar % Y₂O₃ and 47.88 molar % ZrO₂. The chart shows a sputter erosionrate of between 0.30 and 0.35 nm/RFhr for a fifth example solid sinteredceramic article (example 5+) composed of 57.64 molar % Y₂O₃ and 42.36molar % ZrO₂. The chart additionally shows sputter erosion resistancerates for solid sintered ceramics of Er₂O₃, Y₂O₃, Gd₂O₃, Er₃Al₅O₁₂(EAG), 99.8% Al₂O₃, 92% Al₂O₃ and a comparison compound ceramicincluding 63 mol % Y₂O₃, 14 mol % Al₂O₃, and 23 mol % ZrO₂ forcomparison.

FIG. 4 is an additional chart showing erosion resistance of varioussolid sintered ceramic articles to a plasma generated using an N₂/H₂chemistry, in accordance with embodiments of the present invention. Thechart shows an erosion rate of about 10 nm/RFhr for the first examplesolid sintered ceramic article composed of 73.13 molar % Y₂O₃ and 26.87molar % ZrO₂. The chart shows an erosion rate of just over 10 nm/RFhrfor the third example solid sintered ceramic article composed of 64.46molar % Y₂O₃ and 35.54 molar % ZrO₂. The chart shows an erosion rate ofjust over 10 nm/RFhr for the fourth example solid sintered ceramicarticle composed of 63.56 molar % Y₂O₃, 35.03 molar % ZrO₂, and 1.41molar % Al₂O₃. The chart shows an erosion rate of under 15 nm/RFhr forthe second example solid sintered ceramic article composed of 71.96molar % Y₂O₃, 26.44 molar % ZrO₂, and 1.60 molar % Al₂O₃. The chartadditionally shows erosion rates for solid sintered ceramics of Y₂O₃,quartz and HPM for comparison.

FIG. 5 is yet another chart showing erosion resistance of various solidsintered ceramic articles to a plasma generated using an CHF₄/CF₄chemistry, in accordance with embodiments of the present invention. Thechart shows erosion rates of just over 0.05 nm/RFhr for the firstexample solid sintered ceramic article (example 1+), second examplesolid sintered ceramic article (example 2+), sixth example solidsintered ceramic article (example 6+), and third example solid sinteredceramic article (example 3+) defined with reference to FIG. 3. The chartadditionally shows erosion rates of just under 0.75 nm/RFhr for thefifth example solid sintered ceramic article (example 5+) and the fourthexample solid sintered ceramic article (example 4+) defined withreference to FIG. 3. The chart additionally shows erosion rates forsolid sintered ceramics of Er₂O₃, Y₂O₃, Gd₂O₃, EAG, 99.8% Al₂O₃, 92%Al₂O₃ and the comparison compound ceramic for comparison.

FIG. 6A is a chart showing erosion resistance of various solid sinteredceramic articles to a plasma generated using an N₂/H₂ chemistry, inaccordance with embodiments of the present invention. The chart shows anerosion rate of under 15 nm/RFhr for yttria, for the example 4++ ceramicarticle, and for the example 5++ ceramic article. The chart also showsan erosion rate of just under 20 nm/RFhr for silicon and an erosion rateof over 20 nm/RFhr for the comparison compound ceramic. The example 4++ceramic includes Y₂O₃ at a concentration of approximately 37 molar %,ZrO₂ at a concentration of approximately 8 molar %, and Er₂O₃ at aconcentration of approximately 55 molar %. The example 5++ ceramicincludes Y₂O₃ at a concentration of approximately 40 molar %, ZrO₂ at aconcentration of approximately 10 molar %, Er₂O₃ at a concentration ofapproximately 30 molar %, and Gd₂O₃ at a concentration of approximately20 molar %.

FIG. 6B is a chart showing pre-etch and post-etch roughness for solidsintered (bulk) yttria, example 4++, example 5++, silicon and thecomparison compound ceramic. As shown, example 4++ and example 5++ solidsintered ceramics show minimum erosion rate and example 4++ showsminimal roughness change.

TABLE 1 Liquid particle count (LPC) for conductor lid in particles persquare centimeter (p/cm²) Material >=.2 μm >=.3 μm >=.5 μm >=1 μm >=2 μmCompound 24,875 7,417 3,053 772 145 Ceramic Lid Example 1+ 21,706 6,5311,926 719 165

Table 1 shows particle defects measured post cleaning of a conductor lidmade out of a comparison compound ceramic & the first example ceramicmaterial (example1+). The first example ceramic material consists ofY₂O₃ at a concentration of 73.13 molar % and ZrO₂ at a concentration of26.87 molar %. The particle contamination may be measured by performinga liquid particle count (LPC). Each column in the table represents anumber of particles that are at least a particular size.

TABLE 2A metal contamination in 10¹⁰ atoms/cm² Material Ca Cr Cu Fe MgMn Compound <70 <20 <10 40 <50 <5 Ceramic Example1+ <70 <20 <10 26 <50<5

TABLE 2B metal contamination in 10¹⁰ atoms/cm² Material Ni K Na Ti ZnCompound <10 <50 <50 <20 <20 Ceramic Example 1+ <10 <50 <50 <20 <20

Tables 2A and 2B show metal contamination on a wafer processed using asolid sintered ceramic lid of the comparison compound ceramic and thefirst example ceramic material. Metal contamination may be measured byinductively coupled plasma mass spectroscopy (ICPMS). Each column in thetable represents a different metal contaminant. Different formulationsof solid sintered ceramic articles described in embodiments herein havedifferent on-wafer metal contamination levels depending on thecompositions of those solid sintered ceramic articles. Therefore, basedon different on-wafer metal contamination specifications ofmanufacturers, different formulations can be chosen to manufacture thecorresponding chamber components.

TABLE 3 mechanical properties of example solid sintered ceramic articlesElastic Water Hardness Modulus Bulk Density Absorption Material (GPa)(GPa) (g/cm³) (%) Y₂O₃ 9.94 205 4.55 N/A Comparison 13.28 225 4.9  N/ACompound Ceramic Example 1+ 13.27 232 N/A N/A Example 1++ N/A N/A 6.390.035 Example 2++ N/A N/A 6.52 0.030 Example 3++ N/A N/A 6.64 0.032Example 4++ N/A N/A 6.79 0.023

Table 3 shows mechanical properties of the first example (example 1+)solid sintered ceramic article defined with reference to FIG. 2, as wellas additional example solid sintered ceramic articles example 1++,example 2++, example 3++, and example 4++ in comparison to mechanicalproperties of the comparison compound and Y₂O₃ solid sintered ceramicarticles.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentinvention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.”

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the invention should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. An article comprising: a plasma resistant ceramicmaterial comprising 40-60 mol % of Y₂O₃, 35-50 mol % of ZrO₂, and 10-20mol % of Al₂O₃.
 2. The article of claim 1, wherein plasma resistantceramic material further comprises trace amounts of at least one ofSiO₂, B₂O₃, Er₂O₃, Nd₂O₃, Nb₂O₅, CeO₂, Sm₂O₃, or Yb₂O₃.
 3. The articleof claim 1, wherein the article is a chamber component for a plasma etchreactor.
 4. The article of claim 1, wherein the article is a chambercomponent selected from a group consisting of an electrostatic chuck, alid, a nozzle, a gas distribution plate, a shower head, an electrostaticchuck component, and a processing kit ring.
 5. The article of claim 1,wherein the article is a solid sintered ceramic article.
 6. The articleof claim 1, wherein the plasma resistant ceramic material comprises atleast one solid solution comprising the Y₂O₃, the ZrO₂ and the Al₂O₃. 7.The article of claim 1, further comprising: a metal portion, wherein theplasma resistant ceramic material comprises a solid sintered ceramicbody bonded to the metal portion.
 8. The article of claim 1, furthercomprising: a ceramic body, wherein the plasma resistant ceramicmaterial comprises a solid sintered ceramic body bonded to the ceramicbody.
 9. An article comprising: a body; and a plasma resistant ceramiccoating on at least one surface of the body, wherein the plasmaresistant ceramic coating comprises a plasma resistant ceramic materialcomprising 40-60 mol % of Y₂O₃, 35-50 mol % of ZrO₂, and 10-20 mol % ofAl₂O₃.
 10. The article of claim 9, wherein the plasma resistant ceramiccoating is a plasma sprayed coating.
 11. The article of claim 9, theplasma resistant ceramic coating having been deposited by ion assisteddeposition.
 12. The article of claim 9, wherein the plasma resistantceramic material further comprises trace amounts of at least one ofSiO₂, B₂O₃, Er₂O₃, Nd₂O₃, Nb₂O₅, CeO₂, Sm₂O₃, or Yb₂O₃.
 13. The articleof claim 9, wherein the article comprises a chamber component for aplasma etch reactor.
 14. The article of claim 9, wherein the articlecomprises a chamber component selected from a group consisting of anelectrostatic chuck, a lid, a nozzle, a gas distribution plate, a showerhead, an electrostatic chuck component, and a processing kit ring. 15.The article of claim 9, wherein the plasma resistant ceramic materialcomprises at least one solid solution comprising the Y₂O₃, the ZrO₂ andthe Al₂O₃.
 16. A method comprising: creating a mixture of a plurality ofceramic powders comprising Y₂O₃ at a concentration of 40-60 mol %, ZrO₂at a concentration of 35-50 mol % and Al₂O₃ at a concentration of 10-20mol %; and sintering the plurality of ceramic powders to form a solidsintered ceramic article.
 17. The method of claim 16, wherein sinteringthe mixture comprises: heating the mixture to a temperature of1500-2100° C. for a duration of 3-30 hours.
 18. The method of claim 16,further comprising: forming one or more features in the solid sinteredceramic article, the one or more features comprising at least one ofholes, channels or mesas.
 19. The method of claim 16, furthercomprising: bonding the solid sintered ceramic article to a metal base.20. The method of claim 16, wherein the solid sintered ceramic articlecomprises at least one solid solution comprising the Y₂O₃, the ZrO₂ andthe Al₂O₃.